The present invention relates to a fuel gauge for detecting the remaining amount of fuel in the fuel tank.
Various fuel gauges are available for detection of the remaining amount of fuel in the fuel tank. JP-A 9-126080 discloses a fuel pump device provided with a fuel gauge. This fuel gauge is arranged in a fuel tank, and comprises a float with an arm moving vertically with the level of fuel in the fuel tank, and a detection body to which a base end of the arm of the float is supported vertically movably and for detecting the vertical displacement amount of the arm. The detection body comprises a permanent magnet fixed to the base end of the arm for vertical movement therewith and a magnetic-flux detecting element or non-contact detecting element arranged in a position opposite to the permanent magnet. The magnetic-flux detecting element is disposed to face a chamber in which the arm and the permanent magnet move vertically.
With the above structure, when the level of fuel in the fuel tank is displaced, the float moves vertically therewith. And the magnetic-flux detecting element detects the vertical displacement of the arm of the float.
With the fuel gauge disclosed in JP-A 9-126080, however, the magnetic-flux detecting element is placed in fuel and/or fuel vapor, having possible deterioration.
Moreover, when failing to be arranged in a predetermined position opposite to the permanent magnet, the magnetic-flux detecting element is lowered in output accuracy. However, no consideration is given to positioning of the permanent magnet and the magnetic-flux detecting element.